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If the ADCLK854's jitter will effect the output waveforms with 320 MHz

Hi,

I want to ask question about ADCLK854's jitter. I use AD9528 to give ADCLK854 320 MHz. In the datasheet Table 2. There are some jitter in the same bank and all outputs are LVDS's situation. My questions as below:

1.If I have 50+65 ps jitter when all of my outputs are LVDS or just 65 ps because they are in the same part, even in the different bank?

2. In the different bank, can I expect all jitter are the same? Or it will be different in different banks because the 50 ps and 65 ps are maximum value, so it maybe will be 10, 25 and 40 ps in different bank? If the answer is yes, it will effect the output waveforms if I want them to send 320 MHz at the same time, right?

Correct me if I am wrong.

Many thanks.

Mike

  • HI,

    1.If I have 50+65 ps jitter when all of my outputs are LVDS or just 65 ps because they are in the same part, even in the different bank?

    Please do not confound jitter with skew. The 50ps and 65 ps entries refer to the skew between the outputs. 

    50ps max is the max skew between LVDS outputs in the same bank and 65 ps is the skew between all outputs on the same part. Skew means that if you look with the oscilloscope at two different outputs of the ADCLK854, the phase difference between them can be max 65 ps considering the temperature range, voltage supply and process variation.

    In the following, I'll consider that you wanted to talk about skew, not jitter.

     2. In the different bank, can I expect all jitter are the same?

    Yes, the 50ps max skew between LVDS outputs in the same bank  skew specification applies to any bank.

    Or it will be different in different banks because the 50 ps and 65 ps are maximum value, so it maybe will be 10, 25 and 40 ps in different bank? If the answer is yes, it will effect the output waveforms if I want them to send 320 MHz at the same time, right?

    If you buffer out 320 MHz to all outputs, the outputs of the same bank may have max 50 ps skew and if you consider outputs from different banks, they may have max 65 ps skew.

    Petre

  • Hi Petre,

    Thank you for your response

    Mike